Adjustable firearm handguard mounting system

ABSTRACT

An adjustable firearm handguard mounting system configured to facilitate setting the rotation of the handguard relative to a barrel nut and then clamping the handguard to the barrel nut using non-parallel screws.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional application 62/236,970filed on Oct. 4, 2015.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

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REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAMLISTING APPENDIX SUBMITTED ON COMPACT DISC AND ANINCORPORATION-BY-REFERENCE OF THE MATERIAL ON THE COMPACT DISC

Not Applicable

STATEMENT REGARDING PRIOR DISCLOSURES BY AN INVENTOR OR JOINT INVENTOR

Not Applicable

BACKGROUND OF THE INVENTION

This invention relates generally to an apparatus for attaching ahandguard to a firearm.

Modern sporting rifles are popular, among other reasons, because theyare highly configurable. Modern sporting rifles are generally comprisedof a lower receiver and parts and an upper receiver and parts. One parton a complete upper receiver is a handguard. The handguard can beconfigured to serve a variety of functions including providing thermalprotection, providing an attachment point for accessories, and providinga support point which does not touch the barrel near the muzzle. Whencertain accessories are attached to the handguard (e.g. sighting aids),the orientation of the handguard relative to the upper receiver iscritical.

One step of assembling an upper receiver is attaching the handguard tothe stripped upper receiver. A barrel is generally inserted into anupper receiver, indexed using a locating pin on the barrel extensioninto a slot in the upper receiver, and secured with a barrel nut. Thebarrel nut may be configured to interface with features of speciallyconfigured handguards. Handguards which attach to the barrel nut and donot directly touch the barrel may aid accuracy by not introducingunpredictable harmonics caused by contact between the barrel andhandguard or support.

BRIEF SUMMARY OF THE INVENTION

The invention is an apparatus for attaching a handguard to a barrel nut.The barrel nut is textured on the outer circumference and has at leastone groove on the outer surface. The handguard is configured to fit overthe barrel nut. Screws threaded into the handguard against the texturedportion of the nut set and maintain the rotation of the handguard whileand after it is installed. Screws threaded through the handguard clampthe handguard to the barrel nut.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows the barrel nut of the invention. Shown are two groovesconfigured to cooperatively interact with clamping screws. Between thegrooves are a series of radial holes having a flattened surface on theexterior of the barrel nut around each said radial hole. To the right ofthe right-most groove is textured portion of the circumferenceconfigured to interact with rotation adjustment screws.

DETAILED DESCRIPTION OF THE INVENTION

The invention is a novel apparatus for attaching a handguard to a barrelnut. The barrel nut is configured with radial holes which reduce weightand provide an attachment interface used when tightening and looseningthe nut. The barrel nut also contains texturing around a portion of theouter circumference of the nut. The texturing is spaced from the end ofthe nut such that when a rotation adjustment screw is threaded into thehandguard, the screw contacts the texturing. The handguard is configuredwith at least one threaded hole configured to accept a screw to set therotation of the handguard relative to the nut (and an upper receiveronto which the barrel nut is attached). When the handguard is attachedto the barrel nut, at least one rotation adjustment screw is threadedinto the threaded hole in the handguard until the desired amount ofcontact with the texturing on the barrel nut is achieved. In a preferredembodiment, there are two threaded holes (and rotation adjustmentscrews) which are neither parallel nor orthogonal.

The nut is also configured to contain at least one groove. The groove(s)is spaced such that when one or more clamping screws is threaded intothe handguard, the clamping screw(s) pass through the groove(s). In apreferred embodiment, the nut contains two grooves and the handguard isconfigured to accept two non-parallel clamping screws. The mass of thehandguard is minimized, and no additional parts are required, byconfiguring the handguard to accept non-parallel clamping screws.

The handguard is configured with a length-wise gap positioned to overlapwith the barrel nut. The handguard is also configured with at least onehole on one side of the gap aligned with a threaded hole on the oppositeside of the gap. The hole(s) is/are configured to accept a clampingscrew. When the clamping screw(s) is/are tightened, the inner diameterof the handguard is reduced providing a friction fit between thehandguard and barrel nut. In a preferred embodiment, there are twoclamping screws. In a preferred embodiment, the gap does not extendbeyond the portion of the handgard which overlaps with the barrel nut.

The features of the apparatus are designed for the barrel to be insertedinto the upper receiver, the barren nut threaded onto the upperreceiver, and the barrel nut then be tightened onto the upper receiverusing a tool which interfaces with the radial holes in the barrel nut.The handguard is then slid over the barrel nut. The handguard is alignedas desired and the rotation adjustment screws are tightened. Theclamping screws are then inserted into the handguard and tightened.Frictional force between the inside of the handguard and the outside ofthe barrel nut, in conjunction with mechanical locking between rotationadjustment screws and texturing on the barrel nut, prevent the handguardfrom rotating on the barrel nut.

SEQUENCE LISTING

Not Applicable

1. A device for attaching a handguard to a barrel nut comprising: a. agenerally cylindrical barrel nut wherein said barrel nut comprises aninterior configured to cooperatively couple with a firearm and b. ahandguard: (i) said handguard comprising a length-wise barrel nutopening configured to cooperatively interface with said barrel nuthaving an interior diameter configured to slip-fit over said barrel nut,and (ii) said handguard further comprising a length-wise clamping gap inthe circumference of the handguard in at least a portion of thehandguard which is configured to slip-fit over said barrel nut. 2) Thedevice of claim one wherein: a. said barrel nut further comprises atleast one groove in the outer surface and b. said handguard furthercomprises at least one clamping hole: (i) said hole comprising athreaded portion originating at the exterior of the handguard on oneside of said length-wise gap, (ii) said hole passing through thelength-wise gap, and (iii) said hole comprising a threaded portionextending into the handguard on the opposing side of the length-wise gapwherein said hole is configured to align with said groove in the outersurface of said barrel nut and wherein said clamping hole is configuredsuch that a screw passing through the clamping hole passes through saidgroove in the outer surface of said barrel nut. 3) The device of claimtwo wherein: a. said generally cylindrical barrel nut further comprisesa textured portion of the circumference and b. wherein said handguardfurther comprises at least one threaded rotation adjustment holeoriginating at the exterior of said handguard and terminating in theinterior of said handguard in the portion of said handguard which isconfigured to slip-fit over said barrel nut. 4) The device of claimthree wherein: a. said barrel nut further comprises more than one groovein the outer surface, and b. said handguard further comprises more thanone clamping hole. 5) The device of claim four wherein: a first clampinghole is not parallel to a second clamping hole. 6) The device of claimfive wherein: said handguard further comprises more than one threadedrotation adjustment hole. 7) The device of claim six wherein: said oneor more threaded rotation adjustment holes in said handguard are notradial to said barrel nut opening. 8) The device of claim seven wherein:a. said textured portion of said circumference of said barrel nutconsists of parallel depressions spaced to match the thread pitch ofsaid threaded rotation adjustment hole(s), and b. said threaded rotationadjustment hole(s) in said handguard is configured such that the threadsof a screw inserted into said threaded rotation adjustment hole(s)cooperatively interface with the textured portion of said circumferenceof said barrel nut 9) The device of claim six wherein: said barrel nutfurther comprises one or more radial holes. 10) The device of claim ninewherein: said barrel nut further comprises a flattened surface on theexterior of the barrel nut around each said radial hole.